Manufacture of jute yarn



3m E2, 1937. a. MccARDLE ET AL MANUFACTURE OF JUTE YARN 7 Filed Dec. 7,1932 INVENTORS GEORGE MC CARDLE TL-lggi TAGGART ATTORNEYS Patented Jan.12, 1937 UNlTED STATES MANUFACTURE or JUTE YARN George McCardle andThomas Taggart, New York, N. Y., assignors to Chelsea Fibre Mills, NewYork, N. Y., a. corporation of New York Application December 7, 1932,Serial No. 646,054

11 Claims.

This invention relates to the manufacture of jute yarn, and moreparticularly to a novel process for making a more uniform, stronger, andcleaner yarn than has heretofore been ohtainable.

Jute yarn is ordinarily characterized by thickened portions, known asslubs, which are usually associated with correlative thinnedportions.The slubs seem to be small accumulations of 10, short fibres, theseshort fibres probably having been freer and therefore moved or gatheredmore readily than the long fibres during the drawing of the silverpreparatory to forming the finished yarn. At the same time, thisdisplacement or accumulation of short fibres presumably leaves anattenuated body of long fibres, thereby reducing the diameter of theyarn at the long-fibred portions adjacent the slubs.

These factors in turn weaken the yarn. Furthermore, short fibres, evenwhen not accumulated into slubs, are undesirable because they give theyarn a fuzziness which detracts from its appearance and desirability.

The primary and ultimate. object of the present invention is to minimizethe production of slubs in jute yarn, and to produce a cleaner,stronger, and more uniform jute yarn than has heretofore been known. Acorollary object, or thesame object expressed in its process aspect,

is to minimize the production of short fibres during the manufacture ofthe yarn, or to make the fibre length of the sliver more nearly uniform.This object is fulfilled, broadly, by including in the manufacturingprocess, after the softening step and prior to the carding step, astraightening step in which the previously softened bunches of jute aredrawn out into relatively long straight fibres. The softened jute isrelatively slowly drawn out into a continuous long-fibred sliver withpractically no fibre breakage, and it is this straightened fibre, ratherthan curled twisted bunches of jute, that is subsequently carded. Therelatively harsh high-speed carding action, while breaking the fibre andreducing the fibre length to that desired, does not additionally producequantitiesof to reduce the to make possible simplified and convenienthandling of the material throughout the process, including theconditioning of the jute prior to carding the same; as well as toimprove the conditioning of the jute preparatory to carding the same.

To the accomplishment of the foregoing and such other objects as willhereinafter appear, our invention consists in the process steps andtheir relation one to the other, as herein- 10 after are moreparticularly described in the specification and sought to be defined inthe claims. The specification is' accompanied by a drawing in which:

Fig. l is a side elevation showing the jute 15 straightening machine ofthe present invention,

directly coupled to a jute softening machine and followed by a rollformer;

Fig. 2 is a schematic showing of the conditioning of the jute in rollform under predetermined temperature and humidity conditions;

Fig. 3 is a side elevation of a typical finisher card such as may beused directly after the conditioning stage without the intermediate useof a breaker card;

Fig. 4 is a schematic showing of a conventional drawing frame several ofwhich may be used in the usual manner to draw out the sliver; and

Fig. 5 is an enlarged view of a bit of yarn 30 showing a slub andthinned portion, which frequently occur in jute yarn and which areminimized by the present process.

Jute is received in bales which consist of a large number of so-calledheads of jute com- 35 pressed together under high pressure, each headconsisting of a bunch of stripped jute stalks twisted together to form aseparable unit. The bales are opened, and the heads of jute aresubdivided into smaller bunches which are thrown out in moreconveniently manipulable form but which nevertheless are in a curled ortwisted condition. These bunches of jute are fed or thrown out manuallyon the feed apron of a jute softening machine where the fibre is runbetween a long series of rolls and is at the same time treated by alubricating emulsion which is rained onto the jute during the softeningprocess.

In accordance with current practice, the flattened and softened bunchesof jute leaving the softening machine are picked up by workmen, foldedand stacked, and thereupon transferred to a conditioning, room or binwhere the jute is conditioned for a considerable period of time,

say, twenty-four hours, during which the emulsion is given time tospread over and through and to operate on the fibre.

The jute is next put through a series of standard and well-knownmachines including a. breaker card, a finisher card, a number of drawingframes, and finally a roving frame. The breaker card is provided with afeed apron upon which the conditioned bunches of jute must be thrown outor spread by manual labor. The jute must be loaded upon the apron at apredetermined uniform rate, in order that the continuous sliverdelivered by the machine may be of uni form weight. The breaker cardruns at high speed and has relatively finely distributed pins whichoperate not only to split and silver the fibre, but also to break thesame, the average fibre length of the delivered sliver being, say, teninches, instead of the original stalk length of, say, five or six feet.While the breaker cardthus successfully and desirably transforms thejute into a sliver having a desired average fibre length,itwunfortunately and undesirably produces a considerable quantity ofshort fibre,

which, we believe, is caused by the harsh high-'- The sliver from thebreaker card is collected either in cans or rolls, and a considerablenum- 2 her, say, ten, such slivers are simultaneously fed into afinisher card which again .cards the sliver and draws the same out toapproximately its original weight per unit length. The average fibrelength is but little, if at all, reduced in the finisher card. Thesliver delivered by the finisher card is again collected in cans orrolls, and is fed, with appropriate doublings, to a series of drawingframes in which the draft is made greater than the doublings ormultiplication of slivers, so that the delivered sliver is attenuated orreduced in weight per unit of length. Finally, the sliver is fed to anappropriate roving frame in which it is drawn out to its ultimate weightand twisted and wound upon bobbins.

The yarn thus produced appears uniform to the eye, particularly whenwound in balls or on a bobbin. However, if wound with individuallyspaced strands on a. blackboard to provide acontrasting background, itis found that the yarn is not uniform but is characterized by numerousthickened and thinned p1aces,'as well as considerable fuzz. Thus,referring to Fig. 5 of the drawing, the strand of yarn 2 is thickened at4 to form a slub, and is thinned at 6, the normal diameter not beingregained until aboutat the point 8. places or slubs 4 consist ofaccumulations of short fibres which have been drawn into bunches in thedrawing frame or roving frame, while the thinned or attenuated portions6 consists of remaining long fibres. These non-uniformities in the yarnreduceits strength. The slubs and the thinned parts are ordinarilyassociated in the yarn, being'related as shown in Fig. 5, therebyevidencing the fact that one is presumably the cause of the other.However, it should be understood that our invention is a change inprocess which may in some aspects be deemed an empirical discovery, andthat all theory and explanatory matter herein offered, while based onlong and careful study and investigation, and while believed sound andtrue, constitutes no essential part of the invention.

In accordance with the present invention,

It is our belief that the thickened particularly to Fig. 1, thereof, aconventional.-

softening machine is indicated at I2, this machine comprising .--aseries of lower rollers rotated through appropriate gearing from a drivepulley I 4, and a series of upper rollers forced yieldably downward byappropriate compression springs in housings [6. The bunches of jutestalks are manually thrown or spread upon. a

feed apron I8, and are thereupon compressed and repeatedly bent by theoperation of the rollers. At the same-time, an appropriate lubricatingemulsion is preferably rained down upon the jute during'its passage,through the softening machine, apparatus for this purpose beingindicated at 20.

The bunches of softened jute are fed directly from the softening machineI2 to a straightener 22, an appropriate transfer belt or apron 24 beingused to interconnect the same if the units are spaced apart. Thestraightener 22 may best be described by its close similarity to abreaker such as is used for hard fibre, say, Manila hemp or Mexicansisal. It comprises a frame 25 provided at one end with feed rollers 26,and provided at its opposite end with delivery rollers 28. Intermediatethe feed and delivery ends of the machine are provided two sets ofrelatively long, widely spaced pins 30 and 32, these pins being mountedon endless chains driven through appropriate gearing 40, 42, and 44interconnected and driven by suitable mechanism. The straightof fibrebreakage takes place in the machine. V

Instead, the fibre is simply drawn out into a continuous long-fibredsliver. The softened bunches of jute leaving the softening machine l2are curled, twisted, and separable one from another. After passingthrough the straightener 22, the

stalks are subdivided or split .somewhat, but,

more importantly, are drawn out and straightened, and are delivered inthe form of a continuous sliver which may be collected in a can orformed into a roll by a roll former 46, but without substantial breakageof the fibre. I

The fact that the straightener delivers the jute in the form of acontinuous sliver is in itself a great convenience throughout theremainder/ of the process. The"sliver may be formed into rolls, as shownin Fig. 1, and conditioned while in convenient roll form. Thus,

referring to Fig. 2, the rolls of long-fibred sliver 48 are stacked in aconditioning room 50 which may then be simply. an enclosed chamber in.which the temperature and humidity condi tions are preferablycontrolled so as to prevent evaporation of the water in the conditioningemulsion. The fibres, being closely compacted, tend of themselves tohold the emulsion, and uniform distribution of the same throughout themass of fibre is very greatly facilitated. To

fully understand the advantages thus obtained, it may be pointed outthat it frequently is the practice to take the softened bunches of juteand to place them in large bins where they are trampled down to keep thesame in compacted or compressed condition during the conditioning stageor treatment. With the present process, manual handling of individualbunches of jute is entirely dispensed with once the jute has been fed tothe softening machine, and the splitting or slivering of the jute priorto conditioning the same better exposes the fibre to the conditioningfluid, while if the sliver is formed into rolls, the fibre is compactedduring the conditioning period without trampling or special handling ofany kind.

The rolls 48 of long-fibred sliver may next be fed into a breaker cardwhich may be of conventional type or which, more preferably, may bemodified to take advantage of the continuous sliver supplied thereto. Aplurality of slivers may be simultaneously fed into the breaker card toaverage out the weight of the delivered sliver. Manual feeding ofbunches of jute to the breaker-card is then dispensed with, and this isimportant because the jute must be fed to the breaker card at a uniformrate in order to avoid variations in the weight of delivered sliver.What is most important, however, is that with jute preliminarilystraightened in accordance with the present invention, the high-speedand relatively harsh carding action of the breaker card, while reducingthe fibre length to a desired value, does not at the same time producesubstantial quantities of short fibres. With the present invention anaverage fibre length may be obtained which is more nearly uniform, thequantity of extremes or variations being greatly reduced, and the actualfibre length being brought nearer to the mean or average fibre length.

In fact, we have found that the improvement in the nature of the cardingaction is so pronounced and so marked that the breaker card may beomitted entirely, permitting the conditioned sliver to be fed directlyto a finisher card. Thus, referring to Fig. 3 of the drawing, a finishercard is indicated at 52 and may be of conventional type. That here shownis ar ranged for roll feed and roll delivery. A series say, ten, of therolls 48 are supported in front of the machine and are simultaneouslyfed thereto in continuous slivers indicated at 50. A

single finished sliver, indicated at 52', is preferably rolled inappropriate roll forming mechanism 54, the finished rolls 56 beingcollected in an appropriate trough 58.

The process from this point on is conventional and includes. multiplyingand drawing the sliver in appropriate drawing frames, and finallydrawing and twisting the sliver in an appropriate roving frame to formjute yarn. A typical drawing frame is indicated schematically in Fig. 4,the drawing frame 69 being supplied with a plurality, say, four, slivers62 from corresponding rolls 5B. The draft of the frame 50 is madegreater than the doubling or multiplication of feed slivers, so that areduced or attenuated sliver 64 is delivered from the drawing frame.This may be formed into a roll, as heretofore described, or may, moresimply, be collected in an appropriate can 66. If the sliver is to befurther reduced, it may be run through additional and generally similardrawing frames. Doublings may be obtained by simply feeding sliverssimultaneously from several of the cans 66 to the next drawing frame.The sliver is finally passed through a conventional roving frame whereit is drawn to desired weight and twisted to form the finished juteyarn.

It is believed that the process of the present invention, and the manyadvantages thereof, will be apparent from the foregoing detaileddescription. The improved uniformity of fibre length in the sliver afterthe carding action is of tremendous value. There is a marked reductionin quantity of slubs, and a corresponding improvement in the strengthand uniformity of the yarn, as well as an improvement in appearance andreduction in fuzz. We have devised an unusually stringent test for theyarn, which permits actual quantitative weighing of the ounces of slubsfor a given length, say, one thousand yards of yarn. reduces thequantity of slubs to a matter of only 25% of the amount heretoforeproduced. The more uniform fibre length is also of advantage in theactual handling of the various slivers through the drawing and rovingframes, for breakage or discontinuity of the sliver seldom occurs.

The breaker card may be eliminated entirely,

The present process thereby dispensing with the necessity for a machinewhich is large, highly complex, and extremely costly. Of course, thestraightening machine is added, but this is an extremely simple andinexpensive machine compared to the breaker card. It may not be amiss toemphasize the fact that while in a sense the breaker card has beenreplaced by the straightener, and the straightener structurallyresembles a hard hemp breaker, the -straightener as employed by us isnot a breaker, and no fibre breaking action is contemplated or desiredand only a negligible amount of fibre breakage takes place. Thestraightener pins are long and widely spaced, and are moved relativelyslowly with but little draft or step-up ratio in the movement of one setof pins relative to the other. The pins of the straightener do not hackor strike the fibre, as in the case of a breaker card, but insteadrelatively slowly and gradually draw the jute into a straightenedcontinuous sliver form, the fibres being left long but being laidparallel. This continuous and straightened or combedout fibre eases theordinarily harsh action of the high-speed card, whether breaker card orfinisher card, and, while this belief is advanced by way of explanationand not limitation of the invention, it is our belief that this in turnminimizes the production of short fibres. The present disclosure may beconsidered as an empirical discovery making for tremendously improvedand directly measurable results. Matters other than direct descriptionof the improved process are offered simply in an attempt to explain thegratifying and beneficial improvement obtained by practicing the presentinvention.

Other advantages of the improved process are: the reduction in manuallabor required; the convenience of handling the fibre when conditioningthe same; the automatic compacting and compressing of the fibre duringthe conditioning period; and the splitting or subdivision of the fibreprior to conditioning, permitting better penetration and distribution.of the emulsion.

It will be understood that while roll feed and delivery is indicated atvarious points in the process, this is not essential, for can deliveryand feed may also be employed. In fact, the

process as herein described partially employs roll feedand partiallyemploys can feed, and the stage in the process at which transition fromone to the other is made, as well as the use of one or the otherthroughout-the entire process, is optional. Roll delivery is of value atthe beginning of the process because of its convenience whenconditioning the fibre, but even then is notessential. The importantthing is the handling of the fibre at all times subsequent to itsinitial feed to the softening machine in the form of a continuous,sliver, but the particular manner in which this convenient sliver ishandled is of less importance. It will also be understood that twocarding stages may be retained, even though one may be and preferably iseliminated.-

It will therefore be apparent that while we have shown and described themethod bf our invention in preferred form, many changes andmodifications may be made in the steps thereof, without departing fromthe spirit of the invention, defined in the following claims.

In the appended claims we use the term combing for convenience, but thisterm is not intended to have its usual technical meaning in the textileart, but instead means the slow splitting, parallelizing, and sliveringaction herein described. It is used in the sense of gilling rather thanin the sense of carding,hackling or breaking.

We claim:

1. In the manufacture of jute yarn, the method which includes softeningthe jute, slow- 1y combing, staightening and slivering the sofing, andtwisting the sliver in conventional mantened jute without substantialbreakage, carding the long-fibred sliver, and, finally doubling,drawcarding the conditioned sliver, and finally doubling, drawing, andtwisting the sliver in conventional manner. 4. In the manufacture ofjute yarn, the method which includes softening the jute, slowly combingand straightening and slivering the softened jute without substantialbreakage, conditioning the long-fibred sliver by storing it away forlong exposure to a conditioning fluid, carding the same in a finishercard, and finally dou bling, drawing, and. twisting the sliver in conventional manner.

5. In the manufacture of jute yarn, the method of minimizing slubs,which includes softening the jute, slowly combing andstraightenmediately using a breaker. card, and finally douing and'slivering-the softened jute without substantial breakage, conditioningthe long-flbred sliver by storing it away for long exposure to aconditioning fluid, thereafter breaking and finishing the same in afinisher card without interbling, drawing, and twisting the sliver inconventional manner.

6. In the manufacture of jute yarn, the method which includes slowlycombing and transforming the juteinto a continuous long-fibred' sliverim'- mediately followingthe softening step, thereafter conditioning thesliver by storing it away for long exposure to a conditioning fluid, andthen carding the sliver by feeding the fibre in sliver form toacontinuous long-fibred sliver without substantial breakage, and rollingthe same into rolls, all immediately following the softening step,thereafter conditioning the samewhile in roll form by storing it awayfor long exposure to a conditioning fluid, and 'then carding the sliverby feeding the fibre in sliver form to a carding machine.

9. In the manufacture of jute yarn, the method of promoting uniformityof fibre length, which includes softening the jute in conventionalmanner, then slowly combing, splitting and drawing out the softenedstalks into a straightened continuous sliver, said combing action'beingused in substitution for the conventional harsh, highspeed breaker cardaction, and after said combing action feeding the fibre in sliver formto a carding machine, the introduction of the combingstage ahead of thecarding stage operating to minimize short fibres and slubs.

10. In the manufacture of jute yarn, the method of promoting uniformityof fibre length which includes softening the jute in conventional mannerincluding the application of a conditioning fluid thereto, then slowlycombing, splitting and drawing out the softened stalks into astraightened continuous sliver, said combing action being used insubstitution for the conventional harsh high-speed breaker'card action,conditioning the fibre while handling the same in unbroken sliver formby storing it away to permit long exposure to the conditioning fluid,and thereafter feeding the fibre in sliver form to a carding machine,the

introduction of the combing stage operating to minimize short fibres andslubs. 11. In the manufacture of jute yarn, the method of promotinguniformity of fibre length which includes softening the jute inconventional manner including the application of a conditioning fluidthereto,- then slowly combing, splitting and drawing out the softenedstalks into a straightened'continuoussliver, said combing action beingused in substitution for the conventional harsh high-speed breaker cardaction, winding the sliver into rolls, conditioning the sliver whilekeeping the same in rolled form by storing the rolls away to permit longexposure to the conditioning fluid, and thereafter feeding the fibre insliver form to a carding machine, the introduction of the combing stageoperating to minimize short fibres and slubs.

GEORGE MCCARDLE. THOMAS TAGGART.

